18851564601 has 9 divisors (see below), whose sum is σ = 27230632741. Its totient is φ = 12567435132.

The previous prime is 18851564591. The next prime is 18851564617. The reversal of 18851564601 is 10646515881.

The square root of 18851564601 is 137301.

It is a perfect power (a square), and thus also a powerful number.

18851564601 is a `hidden beast` number, since 1 + 8 + 85 + 1 + 564 + 6 + 0 + 1 = 666.

It is a tau number, because it is divible by the number of its divisors (9).

It is not a de Polignac number, because 18851564601 - 2⁵ = 18851564569 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18851564621) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 389020 + ... + 434786.

Almost surely, 2^18851564601 is an apocalyptic number.

18851564601 is the 137301-st square number.

18851564601 is the 68651-st centered octagonal number.

It is an amenable number.

18851564601 is a deficient number, since it is larger than the sum of its proper divisors (8379068140).

18851564601 is an frugal number, since it uses more digits than its factorization.

18851564601 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 91540 (or 45770 counting only the distinct ones).

The product of its (nonzero) digits is 230400, while the sum is 45.

It can be divided in two parts, 188515 and 64601, that added together give a triangular number (253116 = T₇₁₁).

The spelling of 18851564601 in words is "eighteen billion, eight hundred fifty-one million, five hundred sixty-four thousand, six hundred one".